The present invention relates to a honeycomb structure. More specifically, the present invention relates to a honeycomb structure capable of inhibiting pressure loss from increasing upon trapping particulate matter in exhaust gas and effectively combusting and removing the trapped particulate matter.
There is a growing requirement for removing particulate matter in exhaust gas discharged from internal combustion engines such as an automobile engine, a construction machine engine, and an industrial machine stationary engine, other burning appliances, and the like in consideration of an influence on environment. Therefore, a honeycomb structure made of ceramic or the like is widely used as a filter (diesel particulate filter: DPF) for removing particulate matter. As a DPF, there is used a filter having a structure where predetermined cells having openings on one end and plugged end portions on the other side and the other cells having plugged end portions on one end and openings on the other side are alternately disposed. When it is used, a fluid (exhaust gas) is allowed to flow into the structure from one end portion where the predetermined cells have openings, and the exhaust gas is passed through the partition walls and flow out to the other cells as a permeated fluid, which is discharged from the other end portion where the other cells are open. Thus, particulate matter in exhaust gas can be trapped and removed by the partition walls.
In addition, in the DPF, a catalyst is sometimes loaded inside pores or the like of the partition walls in order to combust and remove trapped particulate matter (see, e.g., JP-Y-2607898, JP-A-2007-289902, and JP Application 2006-36185).